/*
 * Author: Benedikt Sauter
 * Author: Peter Huewe, Hubert Hogel
 * All rights reserved.
 *
 * Short descripton of file:
 *
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions 
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright 
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above 
 *     copyright notice, this list of conditions and the following 
 *     disclaimer in the documentation and/or other materials provided 
 *     with the distribution.
 *   * Neither the name of the FH Augsburg nor the names of its 
 *     contributors may be used to endorse or promote products derived 
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "common.h"
#include "protocol.h"
#include "i2c.h"

void i2c_parser(char *buf)
{
  switch(buf[0]){
    case CMD_I2C_INIT:
      i2c_init_usb();
    break;
    case CMD_I2C_DEINIT:         
      i2c_deinit_usb();
    break;
    case CMD_I2C_BITRATE:  
      i2c_set_bitrate_usb((int)buf[2]);
    break;
    case CMD_I2C_SEND_BYTES:
      //void i2c_send_bytes_usb(int address,int len, int timeout,char * data)
      i2c_send_bytes_usb((int)buf[3],(int)buf[1]-4,(int)buf[2],&buf[4]);
    break;
    case CMD_I2C_RECV_BYTES:
      i2c_reveice_bytes_usb((int)buf[3],(int)buf[1]-4, (int)buf[2]);
    break;
    case CMD_I2C_SEND_START:
      i2c_send_start_usb();
    break;
    case CMD_I2C_SEND_STOP:
      i2c_send_stop_usb();
    break;
    default:
      answer[0]=buf[0];
      answer[1]=RSP_UNKOWN_CMD;
      answer[2]=0;
      CommandAnswer(3);
  }
}


unsigned char i2c_get_twsr(void)
{
  return (TWSR & 0xF8);
}


void i2c_wait_for_complete(void)
{
  while (!(TWCR & (1<<TWINT))){
    //do nothing just wait
    ;
  }
}



void i2c_init_usb(void)
{
  answer[0]=CMD_I2C_INIT;
  answer[1]=(unsigned char)i2c_init();
  answer[2]=0;
  CommandAnswer(3);
}

int i2c_init(void)
{
  TWCR |= (1<<TWEN);
  octopus.ports[12]=PIN_SCL;
  octopus.ports[13]=PIN_SDA;
  
  return RSP_OK;
}


void i2c_deinit_usb(void)
{
  answer[0]=CMD_I2C_DEINIT;
  answer[1]=(unsigned char)i2c_deinit();
  answer[2]=0;
  CommandAnswer(3);
}

void i2c_deinit(void)
{
  TWCR &= ~(1<<TWEN); // deinit
  octopus.ports[12]=PIN_OUT;  // this is wrong!
  octopus.ports[13]=PIN_OUT;  // this is wrong!

  return RSP_OK;
}


void i2c_set_bitrate_usb(int speed)
{
  answer[0]=CMD_I2C_BITRATE;
  answer[1]=(unsigned char)i2c_set_bitrate(speed);
  answer[2]=0;
  CommandAnswer(3);
}

int i2c_set_bitrate(int speed)
{
  if(speed==1)
    //TWBR = 12;  // 400 kHz
    TWBR = (F_OSC / 400000UL - 16)/2; 
  else if (speed==2)
    TWBR = (F_OSC / 250000UL - 16)/2; 
  else if (speed==3)
    TWBR = 72;  // 100kHz
    //TWBR = (F_OSC / 100000UL - 16)/2; 
  else {
    return RSP_ERROR; // unkown speed
  }
  //TWBR = 72;  // 100kHz
  TWSR &= ~((1<<TWPS1) | (1<<TWPS0));
  TWSR |= (0<<TWPS0); //buf[4]
  return RSP_OK;
}


void i2c_send_start_usb(void)
{
  answer[0]=CMD_I2C_SEND_START;
  answer[1]=(unsigned char)i2c_send_start();
  answer[2]=0;
  CommandAnswer(3);
}

int i2c_send_start(void)
{
  i2c_get_twsr();
  TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
  i2c_wait_for_complete();
  return RSP_OK;
}


void i2c_send_stop_usb(void)
{
  answer[0]=CMD_I2C_SEND_STOP;
  answer[1]=(unsigned char)i2c_send_stop();
  answer[2]=0;
  CommandAnswer(3);
}


int i2c_send_stop(void)
{
  TWCR = (1<<TWINT)|(1<<TWEN)|(1<<TWSTO);
  return RSP_OK;
}


void i2c_send_bytes_usb(int address,int len, int timeout,char * data)
{
  //i2c_send_byte((char)address << 1);  /* (00010000<<1) | W */

  int i;
  for(i=0;i<len;i++)
    i2c_send_byte(data[i]);

  answer[0]=CMD_I2C_SEND_BYTES;
  answer[1]=RSP_OK;
  answer[2]=0;
  CommandAnswer(3);
}

int i2c_send_byte(char buf)
{
  TWDR = buf;
  TWCR = (1<<TWINT) | (1<<TWEN);
  i2c_wait_for_complete();
  return 0;
}

void i2c_reveice_bytes_usb(int address,int len, int timeout)
{
    /* receive */
    //i2c_get_twsr(); 
    //print_hex(s);

    //i2c_send_start();
    /* slave address = 0x10; */
    //buf[3] = (0x10 << 1)|1;  /* (00010000<<1) | R */
    //i2c_send_byte( (0x10 << 1)|1);
    
    
  answer[0]=CMD_I2C_RECV_BYTES;
  answer[1]=RSP_OK;
  answer[2]=1;
  answer[3]=i2c_receive_byte();
  CommandAnswer(5);
}


unsigned char i2c_receive_byte(void)
{
  TWCR = (1<<TWINT) | (1<<TWEN);
  i2c_wait_for_complete();
  return TWDR;
}

